Air treatment system for a closable room, in particular for a cabin, of a vehicle

Abstract

An air treatment system is described, for a closable room of a vehicle, comprising: an air conditioning device provided with a fan and connectable to the room; an inlet opening for outside air, connected to the air conditioning device; a filtration device for filtering the outside air entering from the inlet opening; a recirculation port; a valve assembly provided with a shutter member, interposed between the inlet opening, the recirculation port and the air conditioning device and movable between a plurality of operating positions, in which it varies the shares of air coming from the inlet opening and the recirculation port; and a control unit to adjust the operating position of the shutter member so as to control the shares of air being drawn from the inlet opening and from the recirculation port and to maintain a predetermined value of overpressure in the room with respect to the outside.

The invention claimed is: 
     
       1. Air treatment system ( 1 ,  1 ′) for a closable room ( 2 ) of a vehicle ( 3 ), in particular for a cabin of the vehicle itself, said system ( 1 ,  1 ′) comprising:
 a box ( 5 ) closed outwardly and connectable to said room ( 2 ); 
 an air conditioning device ( 6 ) located inside said box ( 5 ), provided with at least one fan ( 7 ) and connectable to said room ( 2 ) by means of at least one supply duct ( 8 ) for supplying conditioned and pressurized air to the room ( 2 ) itself; 
 at least a first inlet opening ( 9 ) for external air, obtained in said box ( 5 ) and connected to said air conditioning device ( 6 ); 
 at least a first filtration device ( 11 ) carried by said box ( 5 ) and located at or near to said first inlet opening ( 9 ) to filter external air before it reaches said air conditioning device ( 6 ); 
 at least one recirculation port ( 15 ,  15 ′) to allow in use recirculation of air present in said room ( 2 ) to said air conditioning device ( 6 ); and 
 a valve assembly ( 16 ) for controlling at least the inflow of outside air to said air conditioning device ( 6 ); 
 characterized in that said valve assembly ( 16 ) comprises at least one first shutter member ( 30 ,  30 ′), in particular a door pivotable about a respective axis, interposed between the first inlet opening ( 9 ), the recirculation port ( 15 ,  15 ′) and the air conditioning device ( 6 ) and movable between a plurality of operating positions included between a first limit operating position, in which the door completely closes the connection between the first inlet opening ( 9 ) and the air conditioning device ( 6 ) and allows the connection between the recirculation port ( 15 ,  15 ′) and the air conditioning device ( 6 ) itself, and a second limit operating position, in which the door completely closes the connection between the recirculation port ( 15 ,  15 ′) and the air conditioning device ( 6 ) and allows the connection between the first inlet opening ( 9 ) and the air conditioning device ( 6 ) itself; 
 in that, in the movement between said operating positions interposed between said first and second limit operating positions, said first shutter member ( 30 ,  30 ′) varies by predefined amounts the shares of air coming from said first inlet opening ( 9 ) and said recirculation port ( 15 ,  15 ′); and 
 in that the treatment system further comprises a control unit ( 32 ) configured to adjust the operating position of said first shutter member ( 30 ,  30 ′) so as to control the shares of air being drawn from said first inlet opening ( 9 ) and from said recirculation port ( 15 ,  15 ′) and to maintain a predetermined value of target overpressure (P 0 ) in said room ( 2 ) with respect to the external pressure. 
 
     
     
       2. A system according to  claim 1 , wherein said valve assembly ( 16 ) is arranged at a circuit node ( 22 ) interposed at least between said first inlet opening ( 9 ), said recirculation port ( 15 ,  15 ′) and said air conditioning device ( 6 ). 
     
     
       3. A system according to  claim 1 , wherein said control unit ( 32 ) comprises:
 a pressure sensor ( 33 ) configured to be arranged arranged in use inside said room ( 2 ) and generating as output a pressure signal correlated to the overpressure present in said room ( 2 ) with respect to the external pressure; 
 a first flowmeter ( 34 ) arranged between the first inlet opening ( 9 ) and said first shutter member ( 30 ,  30 ′) and generating as output a flow rate signal correlated to the flow rate of external air taken from the first inlet opening ( 9 ); 
 a first actuator ( 36 ,  36 ′) for moving said first shutter member ( 30 ,  30 ′) between the operating positions; and 
 an electronic control unit (ECU) receiving as input said pressure and flow rate signals and generating as output a control signal for said first actuator ( 36 ,  36 ′) according to the difference between the overpressure detected in use in said room ( 2 ) and said target overpressure value (P 0 ) and according to the external air flow rate limits set for a correct operation of said first filtration device ( 11 ). 
 
     
     
       4. A system according to  claim 3 , further comprising:
 at least one second inlet opening ( 10 ) for outside air, distinct from said first inlet opening ( 9 ), obtained in said box ( 5 ) and connected to said air conditioning device ( 6 ); and 
 at least one second filtration device ( 12 ), having a filtration level different from the filtration level of the first filtration device ( 11 ), carried by said box ( 5 ) and arranged at or near said second inlet opening ( 10 ) for filtering outside air before it reaches said air conditioning device ( 6 ); 
 wherein said valve assembly ( 16 ) comprises a second shutter member ( 31 ,  31 ′), in particular a door pivotable about a respective axis, interposed between said second inlet opening ( 10 ), said recirculation port ( 15 ,  15 ′) and said air conditioning device ( 6 ) and cooperating with said first shutter member ( 30 ,  30 ′) to selectively disable the connection of one of said first and second inlet openings ( 9 ,  10 ) with said air conditioning device ( 6 ). 
 
     
     
       5. A system according to  claim 4 , wherein said control unit ( 32 ) further comprises:
 a second flow meter ( 35 ) arranged between the second inlet opening ( 10 ) and said second shutter member ( 31 ,  31 ′) and generating as output a flow signal for said electronic control unit (ECU) correlated to the flow rate of outdoor air taken from the second inlet opening ( 10 ); and 
 a second actuator ( 37 ,  37 ′) controlled by said electronic control unit (ECU) for moving said second shutter member ( 31 ,  31 ′). 
 
     
     
       6. A system according to  claim 5 , wherein said recirculation port ( 15 ) is disposed upstream with respect to external air flows from said first and second inlet openings ( 9 ,  10 ) and is interposed between said first and second inlet openings ( 9 ,  10 ); wherein said second shutter member ( 31 ) is interposed between said second inlet opening ( 10 ), said recirculation port ( 15 ) and said air conditioning device ( 6 ) and is movable between a plurality of operating positions comprised between a first limit operating position, in which it completely closes the connection between the second inlet opening ( 10 ) and the air conditioning device ( 6 ) and allows connection between the recirculation port ( 15 ) and the air conditioning device ( 6 ) itself, and a second limit operating position, in which it completely closes the connection between the recirculation port ( 15 ) and the air conditioning device ( 6 ) and allows connection between the second inlet opening ( 10 ) and the air conditioning device ( 6 ) itself; and wherein the electronic control unit (ECU) is programmed to selectively place one of said first and second shutter members ( 30 ,  31 ) in the first limit operating position and to adjust the operating position of the other of said first and second shutters ( 30 ,  31 ) so as to control the share of external air flowing to said air conditioning device ( 6 ). 
     
     
       7. A system according to  claim 5 , wherein said recirculation port ( 15 ′) is disposed downstream with respect to the outside air flows from said first and second inlet openings ( 9 ,  10 ) and is interposed between said first and second inlet openings ( 9 ,  10 ) themselves; wherein said second shutter member ( 31 ′) is arranged upstream of said first shutter member ( 30 ′) with respect to air flows coming from said first and second inlet openings ( 9 ,  10 ), is interposed between said first and second inlet openings ( 9 ,  10 ) themselves, and is movable between a first selection position, in which it enables the connection between the first inlet opening ( 9 ) and the air conditioning device ( 6 ) and disables the second inlet opening ( 10 ), and a second selection position, in which it enables the connection between the second inlet opening ( 10 ) and the air conditioning device ( 6 ) and disables the first inlet opening ( 9 ); and in which the electronic control unit (ECU) is programmed to place said second shutter member ( 31 ′) in one of said first and second selection positions and to adjust the operating position of said first shutter member ( 30 ′) so as to control the share of external air flowing to said air conditioning device ( 6 ). 
     
     
       8. A system according to  claim 5 , further comprising a first and a second inlet channel ( 23 ,  25 ) respectively provided with said first and second flow meter ( 34 ,  35 ) and respectively connecting said first and second inlet openings ( 9 ,  10 ) with said circuit node ( 22 ) housing said valve assembly ( 16 ). 
     
     
       9. The system according to  claim 8 , further comprising:
 a first distribution channel ( 40 ) exiting said air conditioning device ( 6 ) and leading into said first inlet channel ( 23 ) downstream of said first flow meter ( 34 ) and upstream of said circuit node ( 22 ) with reference to the flow of external air coming from said first inlet opening ( 9 ); and 
 a second distribution channel ( 41 ) exiting said air conditioning device ( 6 ) and leading into said second inlet channel ( 25 ) downstream of said second flowmeter ( 35 ) and upstream of said circuit node ( 22 ) with reference to the flow of external air coming from said second inlet opening ( 10 ). 
 
     
     
       10. A system according to  claim 9 , wherein said first and second distribution channels ( 40 ,  41 ) are connected respectively to said first and second inlet channels ( 23 ,  25 ) in any operating condition of said valve assembly ( 16 ).